The objective of the Proposed Phase II program is to design, fabricate, and demonstrate a 4 W, 2712 nm fiber laser for use in myringotomy and middle ear surgery. This wavelength is near a maximum in the water absorption spectrum, thereby reducing the laser power requirement. Current myringotomy and middle-ear surgery generally involves the use of a scalpel. Some myringotomy and middle-ear procedures utilize CO2, or various solid-state lasers, but these lasers are large, expensive, and sparsely used. Pulsed lasers result in acoustic pops, frightening children and precluding further usage. Phase I successfully demonstrated a 1 W, continuous wave, 2712 nm fiber laser, capable of burning circular sub-mm diameter holes in a variety of chicken and beef tissue. The Phase II aims will be to scale up the current fluoride fiber laser dimensions, design and apply fiber optical end-coatings for reflectivity control and fiber material passivation, and to fabricate and demonstrate operation of this laser for myringotomy and middle ear surgery applications. Fiber laser efficacy in drilling clean holes into various types of tissue will be tested. Animal models will be used in the second year to determine laser efficacy on living organisms. [unreadable] [unreadable]